Genome-wide analysis of the DnaJ gene family and their expression profiles under salt stress in potato

Saline stress is one of the primary environmental factors affecting global food security, significantly jeopardizing crop quality and yield. DnaJ proteins (DnaJs) are a type of protein that plays an important role in dealing with salt stress for plants. Nevertheless, the comprehensive exploration of the DnaJ gene family and its role in salt stress in potato (Solanum tuberosum L.) is rare. A total of 113 StDnaJs were identified from the potato genome, and they were categorized into three distinct types, with the same type members possessing similar structures. Gene duplication analysis identified twenty-five pairs of duplicated genes, potentially contributing to the expansion of the StDnaJ family in potato. The promoters of StDnaJ genes contained numerous cis-acting regulatory elements linked to light response, plant growth, hormone response, and stress response. A heat map was generated using RNA-seq data, suggesting that they were expressed in roots or leaves under salt stress. We also selected 22 highly responsive members with continuous induction to validate their expression patterns using RT-qPCR, finding that they were significantly induced by salt stress in leaves or roots, with StDnaJ10, StDnaJ21, StDnaJ23, StDnaJ64, StDnaJ94, and StDnaJ107 being induced in both roots and leaves, indicating that these genes may play important roles in salt stress. This study presents an extensive analysis of StDnaJs and provides targeted members for further salt-resistant research in potato.